Locomotive superheater boiler



R. M. OSTERMANN LOCOMOTIVE SUPERHEATER BOILER Oct. 24,

Filed Nov 4 1930 lIi O ct. 24, 1933. R. M. osTERMANN LOCOMOTIVESUPERHEATER BOILER Filed- Nov. 4, 1930 2 Sheets-Sheet 2 INVENTORfiudolphfl. Osfrml) BY FVI w ATTORNEY Patented Oct. 24, 1933 UNITEDsTATEs PATENT OFFICE to The Superheater Company,

New York,

Application November 4, 1930. Serial No. 493,335

3 Claims.

ed only by contact with the furnace gases.Y

While this principle applies obviously to locomotives as well as tostationary plants, difliculties have been encountered in its applicationin the locomotive field, so that, in practice almost without exception,the steam for locomotive engines is superheated in units heated solelyby gas contact.

I have found, however, that the radiant type superheater may be usedsatisfactorily in the fire box of a locomotive, or in'a similar -watercooled fire-box, by placing it out of the direct line of fiow of thegases passing out of the fire-box and at the same time shading thesuperheater somewhat from the radiation. I

The novel features of my invention are pointed out with particularity inthe appended claims. In order that my invention may be fully and clearlyunderstood, however, I will now describe in detail, in connection withthe accom-panying drawings, a superheater installation serving as anillustrative'embodiment of my invention. In said drawings,

Fig. 1 taa/longitudinal central section through the center of alocomotive having a radiant type superheater installed therein inaccordance with my invention, and

Fig. 2 is a transverse vertical section taken through the fire box ofthe locomotive shown in Fig. 1.

In the locomotive illustrated in the drawings, 10 is a boiler shellhaving a steam space 12 and a fire-box 14. Fire-box 14 has the lusualwatercooled side walls 16, 16 extending longitudinally of the boiler andarranged substantially Vertical. In accordance with my invention, aradiant type superheater has its elements 18, 18 arranged in thefire-box 14 closely adjacent to one or both of the side walls 16. Theelements 18 are thereby out of the direct line of fiow of the gases fromthe fire-box to the smoke fiues of the locomotive, the most of whichflow through the central portion of the fire-box. In order, however, toshade the elements 18 somewhat from the direct r'adiation of the burning-fuel I place between each group of elements 18 and the center of thefurnace 14 an apertured water-cooled structure 20. As illustrated, thereare two water-cooled structures 20, and each is built up of a pluralityof curved water tubes 22, 22 which extend from Vertical headers 24, 24to the crown sheet 26 of the locomotive. The headers 24 connect at theirlower ends with the throat 28 of the locomotive at the points 30, 30.The tubes 22 are set far enough apart so that a material amount ofradiation passes between them to strike the elements 18. It will beclear further that the structures such as 20, being exposed to theradiation and to the hot gases in the fire box, generate a great deal ofsteam and thereby add to the capacity of the boiler. Moreover, thecirculation in the tubes 22 of structure 20, being from the headers 24up to the crown sheet 26, carries a greater amount of water to the uppersurface of the crown sheet than would otherwise reach this point in theboiler and thereby protects the crown sheet from over-heating. It willbe obvious that, while the structures 20 are particularly adapted foruse in connection with superheater elements in the fire 'box they may beused without such superheater and, in such case, one may be placed inthe center of the fire-box.

It Will be seen that the superheater elements 18 are close to the watercooled sides of the firebox and that there is nothing between suchelements and the fire-box -wall to hinder radiation from one to theother. Therefore, when elements 18 have attained a temperaturematerially above that of the water in the locomotive boiler, they beginto radiate to one of the fire-box walls 16. As the heat radiated awayfrom a body varies as theA difference between the fourth powers of theabsolute temperatures of itself and the radiation receiving body, thenet amount of heat absorbed by the elements is greatly reduced when theyare delivering steam above the safe temperature of 750 F., therebypermitting the elements to expose a large surface to radiant heat ontheir furnace sides to give them high capacity without the danger ofoverheating. Furthermore, the shading structure 20 has its tubes 22arranged largely transversely to the tubes of elements 18, so that onlyrelatively short sections of the superheating tubes are exposed toradiant heat and the Sections of the superheater tubes intermediate tothose exposed are further protected by counter radiation on theirfurnace sides to the structure 20. Any excess heat in the metal of thetubes of elements 18 therefore does not have to travel any materialdistance along such tubes before being absorbed by cooler metal of theshaded sections or dissipated by radiation and the temperature gradientalong the tubes of the elements and, therefore, the maximum temperaturesare maintained within safe limits in spite of 'the closeness of theelements 18 to the combustion zone.

In case the proportions of the fire-box are such that it is inconvenientto shade the elements 18 to the extent desired by means of aperturedwatercooled structures, baifles 32, 32 (Fig. 2) may be used in additionto the water-cooled structures for this purpose.

steam for the elements 18 is preferably conducted from the forward endof the dry pipe 34 to the fire-box.

I n the arrangement shown, the forward end of dry pipe 34 connects to aheader structure 36 to which are connected the elements 38, 38 of anordinary convection type superheater contained in smoke tubes 40, 40 inthe boiler 10. The inlet ends of the elements 38 connect to thestructure 36 at points 42, 42 and the outlet ends of the elements 38connect to the structure 36 at points, not shown, in a manner analogousto that shown at points 42. From the outlet ends of elements 38 thesteam passes into chambers (not shown) separated from the inlet ends ofelements 38 and thence in known manner by an arrangement not shown intothe chamber 44. From chamber 44 steam passes by pipes 46 downwardlythrough the smoke box 48 and through the tubes 50, 50 which runlongitudinally through the water space of boiler 10 into the forwardportion of flre box 14.

The rear ends of pipes 50 connect to the pipes 52,

52 which extend rearwardly in the lower side portions of the fire box 14parallel to the longitudinal side walls thereof and whichserve asheaders for the inlet ends of the U-shaped superheater elements 18. Theoutlet ends of the elements 18 are connected to headers 54, 54 which areshown as parallel to headers 52 and below and somewhat on the insidethereof. In order that steam may be distributed through the elements 18at a uniform rate, the outlets of the headers 54 are placed at the rearends thereof, thereby obtaining an anti-parallel flow through theelements whereby equal flow resistance is ensured through all the units18 from inlet header 52 to vOutlet headers 54. The headers 54 areconnected by return bends 56 with return pipes 58 which The locomotiveboiler 10 is shown as having the usual dry pipe 34 and the connect attheir forward ends with the rear ends of tubes 59 which run from thefront portion of the fire-box 14 through the water space of the boiler10 and connect to the cylinders (not shown) of the locomotive.

Throttle means for controlling the flow of steam to the superheatingelements 38 and 18 may be placed wherever desired. At present, the twomost common locations for the throttle means are either at 60 in thesteam' dome 62 of the locomotive or else in the chamber 44 adjacent theoutlet ends of the convection heated superheater elements.

It will be understood that I have described herein above only oneembodiment of my invention and that it may be used in stationary boilerswhen desired as well as in locomotives. It will be understood also-thatparts of my invention may be used apart from the others without avoidingcertain of my claims.

Iclaim:

1. The combination with a locomotive type boiler, of a narrow headerhaving its lower end connected to the throat of the boiler and extendingupwardly in the fire box, and a series of spaced curved tubes arrangedsubstantially in the same Vertical plane as said header and connectedinto said header and into the crown sheet of the firebox.

2. The combination of a steam boiler having a fire box having watercooled side walls, superheater elements arranged close to said walls andso as to radiate thereto without obtruction, and water cooled means foronly partially shading said elements from direct radiation originatingin the central portion of said box, said means for partially shading theelements having apertures therein extending largely transversely to thetubes of the superheater elements.

3. The combination with a horizontal fire-tube boiler having an internalfire-box provided with water-cooled side walls, superheater elementsarranged close to one of said walls and so as to radiate to such wallwithout obstruction, and means for only partially shading said elementsfrom radiation originating in the central portion of said box, saidmeans comprising a narrow header having its lower end connected to thefire-box tube sheet of the boiler below the fire tubes and extendingupwardly in the fire-box, and a series of spaced water tubes arrangedsubstantially in the same Vertical plane as said header and connectedinto said header and also into the crown Sheet of the fire-box.

' RUDOLF M. OSTERMANN.

